Background Donor breast milk has been associated with slower growth in the early postnatal period. The macronutrient concentrations of human milk (HM) might be influenced by the various processes used in human milk banks (HMB). The (LTLT) pasteurisation was known to slightly decrease protein and fat content of HM, but the effect of lyophilization has not been described.
Aims To compare the protein composition between raw and LTLT-HM, and between LTLT-HM and lyophilized HM
Methods This was a prospective monocentre study on 22 independent HM batches. Total proteins were measured by 2-D Quant Kit and sIgA, Lysozyme, Lactoferrin by Elisa-kit in Raw/LTLT/ lyophilized HM. Medians of protein concentrations were compared by Wilcoxon paired test.
Conclusion There was a significant decrease in total and immune proteins (sIgA, Lysozyme, Lactoferrin) between raw and LTLT-HM, which may explain less growth when LTLT-HM is used without fortifier, and less antiinfective properties. On the other hand, lyophilization did not further modify the content of total and immune proteins after pasteurisation.
Pasteurisation has got limitations as a process for preserving donor HM. Other techniques must be developed for decontaminating HM.